kobject: kobject_add_internal failed for hci3:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci3: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1525 Read of size 8 at addr ffff88805fdcb7b0 by task kworker/u9:2/15746 CPU: 1 UID: 0 PID: 15746 Comm: kworker/u9:2 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: hci3 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 l2cap_sock_new_connection_cb+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1525 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5884 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 15746: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5260 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2245 sk_alloc+0x3a/0x390 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1925 [inline] l2cap_sock_new_connection_cb+0xe2/0x2e0 net/bluetooth/l2cap_sock.c:1510 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5884 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 18154: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1c1/0x6c0 mm/slub.c:6483 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x626/0x880 net/core/sock.c:2384 l2cap_sock_cleanup_listen+0xe0/0x440 net/bluetooth/l2cap_sock.c:1490 l2cap_sock_release+0x6e/0x270 net/bluetooth/l2cap_sock.c:1451 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x461/0xa90 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805fdcb000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1968 bytes inside of freed 2048-byte region [ffff88805fdcb000, ffff88805fdcb800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805fdcc000 pfn:0x5fdc8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000240(workingset|head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000240 ffff88813fe1b000 ffff88813fe19c88 ffffea0000cc9010 raw: ffff88805fdcc000 0000000800080006 00000000f5000000 0000000000000000 head: 0080000000000240 ffff88813fe1b000 ffff88813fe19c88 ffffea0000cc9010 head: ffff88805fdcc000 0000000800080006 00000000f5000000 0000000000000000 head: 0080000000000003 ffffea00017f7201 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 17345, tgid 17345 (syz-executor), ts 1348585370770, free_ts 1348579821548 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x77/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x35c/0x710 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_node_track_caller_noprof+0x60b/0x7e0 mm/slub.c:5368 kmalloc_reserve net/core/skbuff.c:635 [inline] pskb_expand_head+0x22c/0x1270 net/core/skbuff.c:2312 netlink_trim+0x1b3/0x2c0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0xd6/0x1010 net/netlink/af_netlink.c:1512 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593 __dev_notify_flags+0xf2/0x310 net/core/dev.c:9816 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9849 do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3180 rtnl_changelink net/core/rtnetlink.c:3798 [inline] __rtnl_newlink net/core/rtnetlink.c:3971 [inline] rtnl_newlink+0x15ad/0x1bb0 net/core/rtnetlink.c:4108 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994 page last free pid 17345 tgid 17345 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978 __slab_free+0x24f/0x2a0 mm/slub.c:5573 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_noprof+0x399/0x7b0 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3818 ip6_route_add+0x49/0x1d0 net/ipv6/route.c:3947 addrconf_add_mroute+0x2d1/0x370 net/ipv6/addrconf.c:2551 addrconf_add_dev net/ipv6/addrconf.c:2569 [inline] inet6_addr_add+0x2e4/0xbd0 net/ipv6/addrconf.c:3031 inet6_rtm_newaddr+0xa17/0xe30 net/ipv6/addrconf.c:5063 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x831/0x9f0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 Memory state around the buggy address: ffff88805fdcb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805fdcb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805fdcb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805fdcb800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805fdcb880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================